Z3 is a theorem prover from Microsoft Research.
Z3 is licensed under MSR-LA (Microsoft Research License Agreement). 
See http://z3.codeplex.com/license for more information about this license.
Z3 can be built using Visual Studio Command Prompt and make/g++.

1) Building Z3 on Windows using Visual Studio Command Prompt
   
   python scripts/mk_make.py
   cd build
   nmake

2) Building Z3 using make/g++ and Python
Execute:

   autconf
   ./configure
   python scripts/mk_make.py
   cd build
   make
   sudo make install

It will install z3 executable at /usr/bin, libraries at /usr/lib, and include files at /usr/include.
You can change the installation p

Use the following commands to install in a different prefix (e.g., /home/leo).

  autoconf
  ./configure --prefix=/home
  python scripts/mk_make.py
  cd build
  make
  sudo make install

To uninstall Z3, use

  sudo make uninstall